Tracheal Length Measurement in Intubated Neonates to Guide the Design and Use of Endotracheal Tube Glottic Depth Markings

Abstract

Background: Data on neonatal tracheal length are needed to inform the standardization of safety features for endotracheal tubes (ETTs) such as glottic depth markings. Laryngotracheal airway measurements are available from digital imaging in infants and children but not in neonates. We aimed to determine the tracheal length (TL) of intubated preterm and term neonates. Methods: An observational study was performed on 57 neonates of 22–42 weeks’ gestation and <1 week of age. Two clinicians independently reviewed 153 digital chest radiographs to determine the carina position and TL. TL was measured from carina to mid-C4 (cricoid level). We analyzed interrater agreement (within 0.5 vertebral levels) on the position of the carina and TL. TL was plotted as a function of gestational age and weight, using graphical and regression analyses. Results: Carina position ranged from T3 to T5.5, with an interrater agreement of 95%. On image pairs concordant for carina position, TL determinations were virtually identical between readers (mean difference 0.1 mm, 95% CI −0.5–0.6 mm). Average mid-tracheal length overlies the body of T1. In infants aged less than 32 weeks’ gestation, the mid-trachea lies <20 mm from the carina or the larynx. TL linearly correlates with gestational age, but correlation with birthweight best fits a segmented regression with a node at 1 kg. Conclusions: The functional length of the laryngotracheal airway can be reliably measured in sick neonates. It correlates well with gestational age and birthweight, and this information can inform the redesign of ETT markings to promote the safer use of these devices.

Risk factors and outcomes associated with unplanned intraoperative extubation of the pediatric surgical patient: An analysis of the NSQIP‐P database

“…The vast majority of inadvertent extubation occurred in patients aged <2 years ( n = 118, 72.4%; Figure 1). The increased extubation risk of neonates and infants may be in part attributed to their short tracheas, with preterm neonate tracheal lengths having been measured as short as 2.2 cm 14 . Airway manipulation would therefore leave this population susceptible to inadvertent extubation.…”

“…The vast majority of inadvertent extubation occurred in patients aged <2 years (n = 118, 72.4%; Figure1). The increased extubation risk of neonates and infants may be in part attributed to their short tracheas, with preterm neonate tracheal lengths having been measured as short as 2.2 cm 14. Airway manipulation would therefore leave this population susceptible to TA B L E 2 Univariable analysis of the total cohort.Risk factorMean ± SD/N (%Abbreviations: ASA, American Society of Anesthesiologists; CI, confidence interval; OR, odds ratio; [Ref], referent group; SD, standard deviation; UIE, unplanned intraoperative extubation.…”

Recommendations for nasotracheal tube insertion depths in neonates

“…A distinct category-dependent ETT tip-to-carina distance was determined, with a target ETT tip location at the mid-trachea position ( 10 ). The optimal ETT tip-to-carina distance for each patient was calculated based on data from Szpinda et al and Cerone et al, who measured tracheal lengths during different gestational stages ( Table 1 ) ( 11 , 12 ). The optimal ETT depth for each patient was determined by adjusting the recorded ETT depth by the distance between the recorded and the defined optimal ETT tip position.…”

Indications, Measurements, and Complications of Ten Essential Neonatal Procedures

“…The position of the carina varies between T3 and T5 [ 101 ]. However, the acceptable ETT tip position is range from the upper border of the first thoracic vertebra and the lower border of the second thoracic vertebra [ 102 ]. Chest X-ray is the gold standard method for verification of ETT position.…”